Nanonization techniques to overcome poor water-solubility with drugs

ABSTRACT

Introduction

Most drugs used in therapy have low water-solubility, a factor that could reduce their dissolution rate and oral bioavailability, representing a challenge in pharmaceutical development. Nanonization of drugs is the reduction of particles to nanoscale, increasing the surface area and consequently the saturation solubility and dissolution rate and resulting in higher bioavailability.

Areas covered

This review provides an overview of the consequences of the poor water-solubility and the main strategies applied to increase the solubility of poorly water-soluble drugs. The relationship between the biopharmaceutical classification system and the solubilization process of the drug is also considered. Finally, it includes how drug nanoparticles and nanocarriers, especially lipid-based nanosystems, can overcome these challenges and which of these approaches are already available on the market.

Expert opinion

Due to the growing importance of nanomedicines, especially for applications in poorly water-soluble drugs, it is important to clearly establish the specifications and quality criteria for nanonized drugs to ensure the quality and safety of nanoparticles.

KEYWORDS:

• Bioavailability
• biopharmaceutical Classification System
• dissolution rate
• drug delivery systems
• nanoparticles
• self-emulsifying formulations
• solubility enhancement

Article Highlights

• Drug water-solubility is a limiting step for its bioavailability, mainly for oral absorption of BCS class 2 and class 4 drugs.

• Increasing water-solubility is a constant challenge for the pharmacist; thus, large investments have been made in research and development of new approaches to overcome drug limitations.

• Conventional strategies to promote increased solubility have several utilities but also some demerits such as non-uniform sized particles, difficult to be reproduced, and usually no decrease in toxicity.

• Nanonization strategies outweigh the poor water solubility of drugs and tackle the disadvantages of the conventional approaches.

• Nanocarriers can protect the drug against degradation and enable targeting.

This box summarizes key points contained in the article.

Declaration of interest

The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

Reviewer Disclosures

Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Additional information

Funding

This study was financed in part by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - Brasil (CAPES) - Finance Code 001 and Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq).